在 Java 中，有一些 URL 解析器？

Question

I know there is a URL class in Java, but I need methods to get the file extension of the page (html, php, asp, etc), the country of the domain (ca, au, br, jp, fr, etc) 、页面类型（.net、.org、.gov 等）等。 其中一些方法，我确实使用了字符串处理，但我认为只为此而做的 class 可能更可靠。

Answer 1

我创建了一个简单的 Java class 使 URL 在 ZD52387880E371EA2283817ADZ 中的解析更加容易1。

https://github.com/juliuss/urlplus

它可用于构建 url 并以编程方式修改它们。 它还处理相对 url。

您可以从单元测试中看到它非常全面：

// build a URL
URL u = new URL("http://www.shopobot.com/?search=ipod");

// check the parts of the url were set correctly
assertEquals(u.getProtocol().name(), "http");

u.setFragment("login");
assertEquals(u, "http://www.shopobot.com/?search=ipod#login");

// add a parameter
u.addParameter("abc", "123");
assertEquals(u, "http://www.shopobot.com/?search=ipod&abc=123#login");

// add a duplicate parameter
u.addParameter("abc", "456");
assertEquals(u, "http://www.shopobot.com/?search=ipod&abc=123&abc=456#login");

// remove a parameter
u.removeParameter("search");
assertEquals(u, "http://www.shopobot.com/?abc=123&abc=456#login");

// reset fragment
u.setFragment("");
assertEquals(u, "http://www.shopobot.com/?abc=123&abc=456");

// test an encoded paramter
u.addParameter("encoding", "this code = awesome!");
assertEquals(u, "http://www.shopobot.com/?abc=123&abc=456&encoding=this+code+%3D+awesome%21");

// remove both duplicate parameters
u.removeParameter("abc");
assertEquals(u, "http://www.shopobot.com/?encoding=this+code+%3D+awesome%21");

// change host and port
u.setHost("localhost").setPort(8080);
assertEquals(u, "http://localhost:8080/?encoding=this+code+%3D+awesome%21");

// remove a parameter and add a page number (int parameter)
u.removeParameter("encoding").addParameter("page", 2);
assertEquals(u, "http://localhost:8080/?page=2");

// set the path
u.setPath("electronics/");
assertEquals(u, "http://localhost:8080/electronics/?page=2");
u.setPath("/electronics/");
assertEquals(u, "http://localhost:8080/electronics/?page=2");

// increment a parameter 3 times
u.incrementParameter("page").incrementParameter("page").incrementParameter("page");
assertEquals(u, "http://localhost:8080/electronics/?page=5");
// make sure the correct page number is returned
assertEquals(u.getParameter("page", 1), 5);

// set the page number to 2 and remove it -- setting it to 1
// since 1 is considered default, it is removed completely
u.setParameter("page", 2).decrementParameter("page");
assertEquals(u, "http://localhost:8080/electronics/");

// make sure that page will not be decremented since we're at 1
u.decrementParameter("page");
assertEquals(u, "http://localhost:8080/electronics/");

// test that defaults work
assertEquals(u.getParameter("page", 1), 1);
assertEquals(u.getParameter("page", 10), 10);

// test relative paths
u.setPath("/electronics/photography/");
assertEquals(u.toStringRelative(new URL("http://localhost:8080/")), "electronics/photography/");
assertEquals(u.toStringRelative(new URL("http://localhost:8080/electronics/")), "photography/");
assertEquals(u.toStringRelative(new URL("http://localhost:8080/electronics/photography/")), "");
assertEquals(u.toStringRelative(new URL("http://localhost:8080/electronics/mp3-players/")), "../photography/");
// make sure when paths match, but authority doesn't results in full url return
assertEquals(u.toStringRelative(new URL("http://www.shopobot.com/electronics/photography/")), "http://localhost:8080/electronics/photography/");
assertEquals(u.toStringRelative(new URL("http://localhost:80/electronics/photography/")), "http://localhost:8080/electronics/photography/");
assertEquals(u.toStringRelative(new URL("https://localhost:8080/electronics/photography/")), "http://localhost:8080/electronics/photography/");

// try some more complicated relative paths
u.setHost("x.com").setPath("/a/b/c/d/e.html").setPort(80);
assertEquals(u.toStringRelative(new URL("http://x.com/")),"a/b/c/d/e.html");
assertEquals(u.toStringRelative(new URL("http://x.com/a/b")),"c/d/e.html");
assertEquals(u.toStringRelative(new URL("http://x.com/a/b?q=1")),"/a/b/c/d/e.html");
u.addParameter("q", 1);
assertEquals(u.toStringRelative(new URL("http://x.com/a/b/c/d/e.html")),"?q=1");
assertEquals(u.toStringRelative(new URL("http://x.com/a/b/c/d/e/f/g/h")),"../../../../e.html?q=1");
assertEquals(u.toStringRelative(new URL("x.com/x/y/z/")),"../../../a/b/c/d/e.html?q=1");
assertEquals(u.toStringRelative(new URL("x.com/a/b/c/d/x/y/e.html")),"../../../e.html?q=1");
u.addParameter("f", "a b c");
assertEquals(u.toStringRelative(new URL("x.com/a/b/c/d/x/y/e.html")),"../../../e.html?q=1&f=a+b+c");
u.setFragment("hello").removeParameter("f");
assertEquals(u.toStringRelative(new URL("x.com/a/b/c/d/x/y/e.html")),"../../../e.html?q=1#hello");
assertEquals(u.toStringFull(),"/a/b/c/d/e.html?q=1#hello");

//test parameters with relative paths
u = new URL("facebook.com");
u.addParameter("test", "hi");
assertEquals(u.toStringRelative(new URL("facebook.com/?test=hi")),"");
assertEquals(u.toStringRelative(new URL("facebook.com/?test=hi&hello=hey")),"?test=hi");
u.addParameter("hello", "hey");
assertEquals(u.toStringRelative(new URL("facebook.com/?test=hi&hello=hey")),"");
assertEquals(u.toStringRelative(new URL("facebook.com/?test=hi&hello=hey#wow")),"?test=hi&hello=hey");
assertEquals(u.toStringRelative(new URL("facebook.com/")),"?test=hi&hello=hey");
assertEquals(u.toStringRelative(new URL("facebook.com/#yo")),"?test=hi&hello=hey");
u = new URL("facebook.com/#yo");
assertEquals(u.toStringRelative(new URL("facebook.com/")),"#yo");

//test relative paths with parameter changes
u = new URL("example.com/?param=1");
assertEquals(u.toStringRelative(new URL("example.com/?param=2")),"?param=1");
u = new URL("example.com/?param=1&param=2");
assertEquals(u.toStringRelative(new URL("example.com/?param=1&param=4")),"?param=1&param=2");
u.removeParameter("param");
assertEquals(u.toStringRelative(new URL("example.com/?param=1&param=4")),"/");

// build a new URL to test empty and null parameter values
u = new URL("http://www.google.com/");
u.addParameter("test", "");
assertEquals(u, "http://www.google.com/?test");
assertEquals(u.getParameter("test", "this is not returned"), "");
u.addParameter("this is a test", null);
assertEquals(u, "http://www.google.com/?test&this+is+a+test");
u.addParameter("", "");
assertEquals(u, "http://www.google.com/?test&this+is+a+test");    
u.addParameter(null, "");
assertEquals(u, "http://www.google.com/?test&this+is+a+test");
u.addParameter("", null);
assertEquals(u, "http://www.google.com/?test&this+is+a+test");
u.addParameter(null, null);
assertEquals(u, "http://www.google.com/?test&this+is+a+test");
u.removeParameter("this is a test");
assertEquals(u, "http://www.google.com/?test");
u.removeParameter("");
assertEquals(u, "http://www.google.com/?test");
String[] nullGuy = null;
u.removeParameter(nullGuy);
assertEquals(u, "http://www.google.com/?test");
u.removeParameter("test");
assertEquals(u, "http://www.google.com/");
u.addParameter(" "," ");
assertEquals(u, "http://www.google.com/?+=+");
u.addParameter("+","+");
assertEquals(u.getParameter("+", ""), "+");
assertEquals(u, "http://www.google.com/?+=+&%2B=%2B");
u.removeParameter(" ").removeParameter("+");
assertEquals(u, "http://www.google.com/");

//test fragment encoding
u.setFragment("short");
assertEquals(u, "http://www.google.com/#short");
assertEquals(u.getFragment(),"short");
u.setFragment("/this/is/a/#/<long>/( fragment )/");
assertEquals(u, "http://www.google.com/#/this/is/a/%23/%3Clong%3E/(+fragment+)/");
u.setFragment(null);
assertEquals(u, "http://www.google.com/");

u = new URL("www.wikipedia.org/wiki/USA");
assertEquals(u.matchesAuthority("org"), true);
assertEquals(u.matchesAuthority(".org"), true);
assertEquals(u.matchesAuthority("pedia.com"), false);
assertEquals(u.matchesAuthority("wikipedia.org"), true);
assertEquals(u.matchesAuthority("uwikipedia.org"), false);
assertEquals(u.matchesAuthority(".wikipedia.org"), true);
assertEquals(u.matchesAuthority("en.wikipedia.org"), false);
u.setHost("sub.en.wiki.com");
assertEquals(u.matchesAuthority("com"), true);
assertEquals(u.matchesAuthority("wiki.com"), true);
assertEquals(u.matchesAuthority("en.wiki.com"), true);
assertEquals(u.matchesAuthority("sub.en.wiki.com"), true);
assertEquals(u.matchesAuthority("asub.en.wiki.com"), false);
assertEquals(u.matchesAuthority("a.sub.en.wiki.com"), false);
assertEquals(u.matchesAuthority("sub.en.wiki.com","asub.en.wiki.com"), true);
assertEquals(u.matchesAuthority("a.sub.en.wiki.com","asub.en.wiki.com"), false);

//test no protocol on factory style methods
u = URL.get("www.wikipedia.org/wiki/USA");
u = URL.get("www.wikipedia.org/wiki/USA", u);

u = new URL("shopobot.com");
u.setParameter("will this <#> be encoded?","we've gone batshit crazy! seriously!");
u.setFragment("what's our # again?");
assertEquals(u.toString(),"http://shopobot.com/?will+this+%3C%23%3E+be+encoded%3F=we%27ve+gone+batshit+crazy%21+seriously%21#what's+our+%23+again?");
assertEquals(u.getParameter("will this <#> be encoded?", ""), "we've gone batshit crazy! seriously!");
assertEquals(u.getFragment(), "what's our # again?");

u = new URL("www.en.shopobot.com");
assertEquals(u.getAuthoritySize(), 4);
assertEquals(u.getAuthority(-1),"");
assertEquals(u.getAuthority(0),"");
assertEquals(u.getAuthority(1),"com");
assertEquals(u.getAuthority(2),"shopobot.com");
assertEquals(u.getAuthority(3),"en.shopobot.com");
assertEquals(u.getAuthority(4),"www.en.shopobot.com");
assertEquals(u.getAuthority(5),"www.en.shopobot.com");

u = new URL("en.wikipedia.org:90210/a/b/c/d/e.html?test=true");
assertEquals(u.getChildDirectory("a"),"b");
assertEquals(u.getChildDirectory("b"),"c");
assertEquals(u.getChildDirectory("c"),"d");
assertEquals(u.getChildDirectory("d"),"e.html");
assertEquals(u.getChildDirectory("e.html"),"");
assertEquals(u.getChildDirectory("g"),"");

assertEquals(u.getParentDirectory("a"),"");
assertEquals(u.getParentDirectory("b"),"a");
assertEquals(u.getParentDirectory("c"),"b");
assertEquals(u.getParentDirectory("d"),"c");
assertEquals(u.getParentDirectory("e.html"),"d");
assertEquals(u.getParentDirectory("e"),"");

//test relative url creation
u = new URL("http://www.example.com");
URL u2 = u.resolveRelative("q.html");
assertEquals(u2.toString(), "http://www.example.com/q.html");
u2 = u.resolveRelative("/q.html");
assertEquals(u2.toString(), "http://www.example.com/q.html");
u = new URL("http://www.example.com/abc/");
u2 = u.resolveRelative("q.html");
assertEquals(u2.toString(), "http://www.example.com/abc/q.html"); 

Answer 2

我不确定是否有特定的 class 可以满足您的要求。 先看一下URL class，再看下面的帖子。

您能否分享一个指向 URL 解析实现的链接？

我认为您需要结合从 URL class 返回的数据和您自己的解析算法来获取不可用的少量数据。 不过，这应该很简单，因为它听起来像是主机和路径的最后一个点索引之后的所有内容（如果它们确实存在，则不能保证）。

Answer 3

不，没有这样的 class。 其中一些东西（国家代码）是不适定的和模棱两可的，并且通常无法仅从 URL 确定。 它们不像查找或推理那样解析。 大多数页面没有定义其他内容（文件扩展名）。